1. Field of the Invention
This invention relates to an assembly and method for monitoring the alignment of a workpiece.
2. Introduction to the Invention
A number of methods and devices have been used (or proposed for use) for monitoring the alignment of a workpiece with respect to a reference. A particularly important advance in this art is realized in the application referenced above. This application discloses a device that preferably employs a relatively recently discovered class of materials known as phase conjugators. Phase conjugate materials can provide reflection of radiation along an incident path. The application discloses that the phase conjugate materials can be usefully employed with other elements to the end of providing an advanced and novel monitoring device. The advantages provided by this device include sensitivity to alignment variations for both large and small angle deviations from the reference, great immunity to possible alignment perturbations in the monitoring device itself, and a capability of permitting dynamic corrections to misalignment conditions.